Preoperative Assessment
Anteroposterior, lateral, and oblique radiographs of the elbow should be
made. In addition, an anteroposterior radiograph of the elbow in 45° of
flexion is crucial to an assessment of an osteochondritis dissecans lesion of
the capitellum as well as medial epicondylar fragmentation
(Fig. 1). Conventional
anteroposterior radiographs of the elbow in extension often lead to an
underestimation of the lesion because of its anterior location. The
radiographs should be assessed for capitellar lesions, the state of the
capitellar growth plate, medial epicondylar fragmentation, and intra-articular
loose bodies. Osseous fragmentation of the capitellar lesion indicates that
conservative treatment is not a viable option. Epiphyseal closure of the
capitellum also speaks in favor of surgical treatment.
We recently assessed the utility of magnetic resonance imaging, computed
tomography, and ultrasonography in the diagnosis of this lesion. Magnetic
resonance imaging clearly demonstrates instability of the capitellar lesion,
through such findings as a high-signal-intensity line through the articular
cartilage, a high-signal-intensity interface, and an articular
defect9. Computed
tomography sagittal reconstructions and ultrasonography demonstrate the
features of the capitellar lesion, including osseous fragmentation and
displacement10. In
addition to assessment of the capitellar lesion, it is very important to
determine the presence of any loose bodies in the olecranon fossa, the radial
fossa, the coronoid fossa, the posterior region of the radiocapitellar joint,
or any other parts of the elbow joint. In a few cases, magnetic resonance
imaging and computed tomography reconstruction have shown loose bodies
interposed in the articular space (Fig.
2). Arthroscopy alone without this preoperative information could
not detect these intracartilaginous loose bodies.
Choice of Surgical Procedure
Surgery should be considered for an unstable osteochondritis dissecans
lesion (Table I). Arthroscopy
should be considered when loose bodies are suspected.
The choice of surgical procedure for an unstable capitellar lesion should
be determined according to the ICRS classification
(Table I). We believe that
bone-peg fixation is the best treatment for an ICRS OCD-II lesion. Fragment
fixation and bone-grafting should be done for an ICRS OCD-III lesion. When a
patient has an ICRS OCD-IV lesion, the fragment should be removed and
reconstruction of the articular surface should be considered if the
osteochondral defect is >50% of the capitellar width.
Positions
With the patient under general anesthesia, we prefer the supine position to
perform arthroscopy and other procedures for treatment of the capitellar
lesion, including fragment removal, bone-peg grafting, and osteochondral plug
grafting. This position also facilitates conversion of an arthroscopy to an
open procedure (Fig. 3).
Arthroscopic Fragment Removal
Ten to 20 mL of 1% lidocaine with epinephrine is injected into the elbow
joint. We usually do not use a tourniquet for arthroscopic fragment removal.
The shoulder is held in 90° of flexion and the elbow is elevated until the
upper arm is almost vertical. This position is maintained with skin traction
applied from the forearm to the overhead bar
(Fig. 3). An assistant can
easily control the position of elbow flexion and forearm rotation.
A 23-gauge needle is used to confirm the suitable position and direction of
the portals. For the posterior and posterolateral portals, a sharp blade is
used to penetrate the skin, muscle, and capsule in one push, and to enlarge
the portals by about 1 cm. For the anteromedial and anterolateral portals, a
sharp blade is used only to cut the skin. Subcutaneous tissues are then
bluntly released so as to avoid the cutaneous nerves, especially the medial
and lateral antebrachial nerves (Fig.
4). The muscle and capsule are penetrated with a thin blunt
instrument rather than a sharp scalpel. The portals are made wider with use of
step-up cannulas. Alternatively, small straight forceps are first used and
then gradually are exchanged for larger ones until a 1-cm portal is
created.
A 4-mm-diameter 30° oblique arthroscope is used. We employ forceps to
remove loose bodies. The surgeon must take care not to injure the ulnar nerve
when working in the posteromedial region of the elbow; hence, we use an open
approach in this area. The surgeon also must take care not to injure the
radial nerve while working anterior to the radiocapitellar joint. Multiple
loose bodies may be found in various places
(Fig. 5), and care must be
taken to remove all of the loose bodies.
To remove loose fragments in the posterior aspect of the radiocapitellar
joint and the radioulnar joint, we prefer open surgery because the space
available for arthroscopy is very small. After the tourniquet is set, we use a
2 to 3-cm posterolateral oblique skin incision on a line from the lateral
epicondyle to the posterior aspect of the radioulnar joint. After the muscle
fibers and capsule over the capitellum have been released, we use arthroscopy
to observe and remove the fragments through this mini-open approach. A limited
local synovectomy should facilitate the procedure. Loose fragments are often
packed in a small area of the lateral-central space of the ulnohumeral joint.
In a few cases, loose fragments have been impacted into the articular
cartilage of the ulna (Fig. 6).
We remove these loose fragments in the ulnohumeral joint with use of a
mini-open posterolateral approach.
Postoperatively, elbow immobilization is not required. Early active motion
of the elbow is recommended after simple fragment removal.
Approach for Fragment Fixation and Reconstruction of the Articular
Surface
We prefer a posterolateral approach to the capitellar lesion. The upper arm
is placed on the operative bed with shoulder abduction and the elbow fully
flexed (Fig. 7). A 4 to 6-cm
posterolateral oblique skin incision is made on a line from the posterior edge
of the lateral epicondyle to the posterior aspect of the radioulnar joint
(Fig. 8). After the tourniquet
is set, the skin and fascia are incised. We develop the intermuscular plane
between the extensor carpi ulnaris and anconeus muscles or an intramuscular
plane through the anconeus muscle fibers. The capsule is incised just over the
capitellar lesion, and the incision is elongated from the posterior edge of
the lateral epicondyle to the posterior aspect of the radioulnar joint. It
should be noted that the capsule is very thin over the capitellum, and this
incision is extended a few millimeters into the proximal edge of the annular
ligament. A limited local synovectomy facilitates this procedure. If more
exposure is required, the capsular incision is elongated proximally and
distally. In patients with severe restriction of elbow flexion, the proximal
part of the capitellar lesion cannot be visualized and treated through this
approach, and arthroscopy is used in combination with an open approach.
Direct assessment of the capitellar lesion is performed. Even if the
operative assessment identifies an ICRS OCD-I lesion, we prefer to use two
bone-peg grafts because we believe that bone-peg grafting can be more
effective than elbow rest for ICRS OCD-I lesions if the preoperative
assessment suggests any instability of the fragment.
Fragment Fixation with Bone-Peg Grafts
The skin incision is elongated distally to the olecranon. The lateral
osseous surface of the olecranon crest is explored by retracting the anconeus
muscle insertion subperiosteally to the radial side. Two or three
corticocancellous bone-pegs are harvested at the posterior and lateral surface
of the olecranon crest (Fig.
9). The length of each bone-peg is about 15 mm, and the diameter
is about 3 mm. One of the tips of each bone-peg is fashioned into a
spindle.
The recipient bone core is made by drilling the capitellum. The diameter of
the drill bit should be slightly smaller than that of the bone-peg to achieve
press-fit fixation. During capitellar drilling, the drill is maintained at
90° to the articular surface. Care must be taken not to penetrate the
capitellar growth plate if it is open. Two or three bone-pegs should be placed
to obtain stable fixation and ensure complete healing. During the insertion of
the bone-peg, we first use a bone tamp followed by the butt end of a drill
head to countersink the head of the bone-peg 1 to 2 mm below the surface of
the articular cartilage (Fig.
9). Two bone-pegs should be placed at the medial and central
aspects of an ICRS OCD-II lesion (Fig.
10). Three or more bone-pegs should be placed at the medial,
anterior, and posterior aspects of an ICRS OCD-III lesion
(Fig. 11). The surgeon should
be aware that union is difficult to obtain, and is often delayed, at the
medial aspect of the lesion whereas the lateral side may heal spontaneously. A
splint is applied to immobilize the elbow during the initial three weeks after
bone-peg fixation.
Reconstruction of the Articular Surface with Use of Osteochondral
Plug Grafts from the Lateral Femoral Condyle
After removal of the unstable fragments, cylindrical osteochondral bone
plugs are harvested from the lateral part of the lateral femoral condyle at
the level of the patellofemoral joint
(Fig. 12). During donor and
recipient harvesting, the tube harvester is maintained at a 90° angle to
the articular surface. It sometimes takes time to prepare the recipient bed
because the capitellar bone is sclerotic and hard. Care is taken to direct the
osteochondral plugs toward the center of the capitellum to obtain stable
fixation. Although the thickness of hyaline cartilage and its surface
curvature differ between the elbow and the knee, the plugs must be inserted to
match the spherical articular surface of the capitellum as much as possible.
The articular surface of the osteochondral plug graft should be slightly
depressed, rather than prominent, relative to the capitellar surface
(Fig. 13). The step-off of the
articular surface should be <1 mm. We rarely shave the articular surface of
osteochondral plug graft. Postoperative radiographs may show slight
overpenetration of the subchondral bone of the osteochondral plug graft
(Fig. 13, C) because
the thickness of the articular cartilage of the graft is greater than that of
the capitellum.
The diameter of the osteochondral plug grafts ranges from 6 to 9 mm, and
the length ranges from 9 to 15 mm. One, two, or three plugs should be used,
depending on the size of the individual defect. We do not consider it
necessary to reconstruct the whole of the capitellar defect. Full-thickness
articular defects within 2 to 4 mm of the articular margin will be
spontaneously repaired with fibrocartilaginous tissues. The long-term results
of treatment of small capitellar defects have been good, suggesting that it is
sufficient to reconstruct 50% to 70% of the articular cartilage of the
capitellar defect (Fig.
14).
Care must be taken not to damage the growth plates of the capitellum or
distal part of the femur in patients in whom they are open. The depth from the
subchondral bone to the growth plate must be measured, and the length of the
harvested grafts should be controlled accordingly
(Fig. 15). The indications for
use of osteochondral plug grafts have gradually expanded. To fix an ICRS
OCD-III lesion, we now use two or three osteochondral plugs instead of a
bone-peg or iliac crest bone (Fig.
16).
The elbow is immobilized for one to two weeks after the surgery to reduce
postoperative pain. The knee should be protected from vigorous flexion for
three weeks.
Care After Fragment Fixation and Reconstruction
The postoperative recovery period includes supervised physical therapy that
initially focuses on reducing pain and swelling and regaining a range of
motion. Gentle resistance exercises are begun at three months and progressed
to full resistance after four months. Resumption of an interval throwing
program is initiated at four to five months only if the patient has no elbow
pain, the range of elbow motion has returned to the preoperative level, and
radiographs show healing of the lesion. A full range of sports activities is
permitted six to eight months following the surgery.
CRITICAL CONCEPTSINDICATIONS:Elbow rest and nonoperative management are appropriate for a stable
osteochondritis dissecans lesion that has all of the following findings: an
open capitellar growth plate, localized flattening or radiolucency of the
subchondral bone, and good elbow motion.Surgery should be considered for an unstable lesion that has one of the
following findings: a capitellum with a closed growth plate, fragmentation, or
restriction of elbow motion of =20°.Arthroscopy is indicated for cases that are known or suspected to have
loose bodies.ICRS OCD-II lesions should be treated with fixation and bone-peg
grafting.ICRS OCD-III lesions should be treated with fixation and bone-peg grafting
or an osteochondral plug graft.ICRS OCD-IV lesions should be treated with fragment removal.Reconstruction of the articular surface should be considered if the
osteochondral defect involves >50% of the capitellar width.CONTRAINDICATIONS:Fragment fixation and reconstructive procedures are contraindicated for
patients unwilling to cooperate with elbow rest; nonoperative management or
arthroscopic fragment removal may be indicated for such patients.Any operative reconstructive procedures other than arthroscopy are
contraindicated for chondrolysis.Other procedures, such as débridement arthroplasty, should be
considered for severe osteoarthritis.PITFALLS:Preoperative EvaluationAn anteroposterior radiograph of the elbow in 45° of flexion is
crucial.Conventional anteroposterior radiographs of the elbow often lead to an
underestimation of the lesion size and extent.Preoperative imaging is crucial to assess not only the capitellar lesion
but also the presence of intra-articular and intracartilaginous loose
bodies.Arthroscopic Fragment RemovalLoose bodies are often multiple and located in various places.Arthroscopy alone without preoperative imaging may not detect
intracartilaginous loose bodies.Blunt dissection to create the anteromedial and anterolateral portals is
recommended to avoid damage to adjacent nerves.Care must be taken not to injure the ulnar nerve when it is necessary to
work in the posteromedial region of the elbow.Loose fragments are often packed into a small space of the lateral-central
region of the ulnohumeral joint and are infrequently impacted into the
articular cartilage of the ulna.Approach for Fragment Fixation and Reconstruction of the Articular
SurfaceThe elbow must be fully flexed.The capsule is incised just over the capitellar lesion.A local synovectomy facilitates direct observation.Fragment Fixation with Bone-Peg GraftsTwo bone-pegs should be utilized for an ICRS OCD-II lesion, and three or
more bone-pegs should be used for an ICRS OCD-III lesion.Healing of medial-side lesions is difficult and often delayed, so it is
necessary to perform bone-peg graft fixation in this location.In patients with an open capitellar growth plate, care must be taken not to
penetrate the physis.Reconstruction of the Articular Surface with the Use of
Osteochondral Plug Grafts from the Lateral Femoral CondyleDuring donor and recipient harvesting, the tube harvester should be
maintained at 90° to the articular surface.It is sometimes difficult to prepare the recipient site because the
capitellar bone is sclerotic and hard.The thickness of hyaline cartilage and its surface curvature differ between
the elbow and knee.The articular surface of the osteochondral plug graft should be slightly
depressed, rather than prominent, relative to that of the capitellum.The step-off of the articular surface should be <1 mm.It is sufficient to reconstruct only 50% to 70% of the articular cartilage
of the capitellar defect.Care must be taken not to damage the growth plates of the capitellum or
distal part of the femur in patients in whom they are open.AUTHOR UPDATE:Stable osteochondritis dissecans lesions are very rare. We used magnetic
resonance imaging, computed tomography, and ultrasonography to diagnose the
lesion as stable or unstable. If there are findings of even slight
instability, we believe that the lesion should be treated surgically.Our indication for osteochondral plug grafting has been gradually expanded
because the results relative to pain, range of elbow motion, and return to
sports have been satisfactory. To fix an ICRS OCD-III lesion, we now use two
or three osteochondral plugs instead of a bone-peg or an iliac crest bone
graft. Reconstruction of the articular surface with use of osteochondral plugs
is also recommended for an ICRS OCD-IV lesion if the patient wants to return
to throwing sports.
CRITICAL CONCEPTS
INDICATIONS:
Elbow rest and nonoperative management are appropriate for a stable
osteochondritis dissecans lesion that has all of the following findings: an
open capitellar growth plate, localized flattening or radiolucency of the
subchondral bone, and good elbow motion.Surgery should be considered for an unstable lesion that has one of the
following findings: a capitellum with a closed growth plate, fragmentation, or
restriction of elbow motion of =20°.Arthroscopy is indicated for cases that are known or suspected to have
loose bodies.ICRS OCD-II lesions should be treated with fixation and bone-peg
grafting.ICRS OCD-III lesions should be treated with fixation and bone-peg grafting
or an osteochondral plug graft.ICRS OCD-IV lesions should be treated with fragment removal.Reconstruction of the articular surface should be considered if the
osteochondral defect involves >50% of the capitellar width.
Elbow rest and nonoperative management are appropriate for a stable
osteochondritis dissecans lesion that has all of the following findings: an
open capitellar growth plate, localized flattening or radiolucency of the
subchondral bone, and good elbow motion.
Surgery should be considered for an unstable lesion that has one of the
following findings: a capitellum with a closed growth plate, fragmentation, or
restriction of elbow motion of =20°.
Arthroscopy is indicated for cases that are known or suspected to have
loose bodies.
ICRS OCD-II lesions should be treated with fixation and bone-peg
grafting.
ICRS OCD-III lesions should be treated with fixation and bone-peg grafting
or an osteochondral plug graft.
ICRS OCD-IV lesions should be treated with fragment removal.
Reconstruction of the articular surface should be considered if the
osteochondral defect involves >50% of the capitellar width.
CONTRAINDICATIONS:
Fragment fixation and reconstructive procedures are contraindicated for
patients unwilling to cooperate with elbow rest; nonoperative management or
arthroscopic fragment removal may be indicated for such patients.Any operative reconstructive procedures other than arthroscopy are
contraindicated for chondrolysis.Other procedures, such as débridement arthroplasty, should be
considered for severe osteoarthritis.
Fragment fixation and reconstructive procedures are contraindicated for
patients unwilling to cooperate with elbow rest; nonoperative management or
arthroscopic fragment removal may be indicated for such patients.
Any operative reconstructive procedures other than arthroscopy are
contraindicated for chondrolysis.
Other procedures, such as débridement arthroplasty, should be
considered for severe osteoarthritis.
PITFALLS:
Preoperative Evaluation
An anteroposterior radiograph of the elbow in 45° of flexion is
crucial.Conventional anteroposterior radiographs of the elbow often lead to an
underestimation of the lesion size and extent.Preoperative imaging is crucial to assess not only the capitellar lesion
but also the presence of intra-articular and intracartilaginous loose
bodies.
An anteroposterior radiograph of the elbow in 45° of flexion is
crucial.
Conventional anteroposterior radiographs of the elbow often lead to an
underestimation of the lesion size and extent.
Preoperative imaging is crucial to assess not only the capitellar lesion
but also the presence of intra-articular and intracartilaginous loose
bodies.
Arthroscopic Fragment Removal
Loose bodies are often multiple and located in various places.Arthroscopy alone without preoperative imaging may not detect
intracartilaginous loose bodies.Blunt dissection to create the anteromedial and anterolateral portals is
recommended to avoid damage to adjacent nerves.Care must be taken not to injure the ulnar nerve when it is necessary to
work in the posteromedial region of the elbow.Loose fragments are often packed into a small space of the lateral-central
region of the ulnohumeral joint and are infrequently impacted into the
articular cartilage of the ulna.
Loose bodies are often multiple and located in various places.
Arthroscopy alone without preoperative imaging may not detect
intracartilaginous loose bodies.
Blunt dissection to create the anteromedial and anterolateral portals is
recommended to avoid damage to adjacent nerves.
Care must be taken not to injure the ulnar nerve when it is necessary to
work in the posteromedial region of the elbow.
Loose fragments are often packed into a small space of the lateral-central
region of the ulnohumeral joint and are infrequently impacted into the
articular cartilage of the ulna.
Approach for Fragment Fixation and Reconstruction of the Articular
Surface
The elbow must be fully flexed.The capsule is incised just over the capitellar lesion.A local synovectomy facilitates direct observation.
The elbow must be fully flexed.
The capsule is incised just over the capitellar lesion.
A local synovectomy facilitates direct observation.
Fragment Fixation with Bone-Peg Grafts
Two bone-pegs should be utilized for an ICRS OCD-II lesion, and three or
more bone-pegs should be used for an ICRS OCD-III lesion.Healing of medial-side lesions is difficult and often delayed, so it is
necessary to perform bone-peg graft fixation in this location.In patients with an open capitellar growth plate, care must be taken not to
penetrate the physis.
Two bone-pegs should be utilized for an ICRS OCD-II lesion, and three or
more bone-pegs should be used for an ICRS OCD-III lesion.
Healing of medial-side lesions is difficult and often delayed, so it is
necessary to perform bone-peg graft fixation in this location.
In patients with an open capitellar growth plate, care must be taken not to
penetrate the physis.
Reconstruction of the Articular Surface with the Use of
Osteochondral Plug Grafts from the Lateral Femoral Condyle
During donor and recipient harvesting, the tube harvester should be
maintained at 90° to the articular surface.It is sometimes difficult to prepare the recipient site because the
capitellar bone is sclerotic and hard.The thickness of hyaline cartilage and its surface curvature differ between
the elbow and knee.The articular surface of the osteochondral plug graft should be slightly
depressed, rather than prominent, relative to that of the capitellum.The step-off of the articular surface should be <1 mm.It is sufficient to reconstruct only 50% to 70% of the articular cartilage
of the capitellar defect.Care must be taken not to damage the growth plates of the capitellum or
distal part of the femur in patients in whom they are open.
During donor and recipient harvesting, the tube harvester should be
maintained at 90° to the articular surface.
It is sometimes difficult to prepare the recipient site because the
capitellar bone is sclerotic and hard.
The thickness of hyaline cartilage and its surface curvature differ between
the elbow and knee.
The articular surface of the osteochondral plug graft should be slightly
depressed, rather than prominent, relative to that of the capitellum.
The step-off of the articular surface should be <1 mm.
It is sufficient to reconstruct only 50% to 70% of the articular cartilage
of the capitellar defect.
Care must be taken not to damage the growth plates of the capitellum or
distal part of the femur in patients in whom they are open.
AUTHOR UPDATE:
Stable osteochondritis dissecans lesions are very rare. We used magnetic
resonance imaging, computed tomography, and ultrasonography to diagnose the
lesion as stable or unstable. If there are findings of even slight
instability, we believe that the lesion should be treated surgically.
Our indication for osteochondral plug grafting has been gradually expanded
because the results relative to pain, range of elbow motion, and return to
sports have been satisfactory. To fix an ICRS OCD-III lesion, we now use two
or three osteochondral plugs instead of a bone-peg or an iliac crest bone
graft. Reconstruction of the articular surface with use of osteochondral plugs
is also recommended for an ICRS OCD-IV lesion if the patient wants to return
to throwing sports.